---
title: "Accessibility Checker Rule Help: RPT_Img_LongDescription2"
---
import "../../../styles/ToolHelp.scss"
import { CodeSnippet, Tag } from "carbon-components-react";

<div className="toolHelp">
<Row>
<Column colLg={5} colMd={3} colSm={4} className="toolLeft">

### Who does this affect?

 * Blind people using a screen reader
 * People using text only, monochrome or braille displays
 * People using text-based browsers (e.g., Lynx) or audio interfaces
 * People who turn off image-loading on their web browsers

### Why is this important?

Text alternatives provide important information that cannot be visually perceived by some people. When a short description is not sufficient, the `"longdesc"` attribute can link to a URL containing a longer description of the image.

</Column>
<Column colLg={11} colMd={5} colSm={4} className="toolMain">

<div id="locLevel"></div>

### Verify that the file designated by the `"longdesc"` attribute contains valid HTML content
The `"longdesc"` attribute must reference HTML content

[IBM 1.1.1 Non-text content](http://www.ibm.com/able/guidelines/ci162/non_text_content.html) | [WCAG 2.1 technique H45](https://www.w3.org/WAI/WCAG21/Techniques/html/H45)

<div id="locSnippet"></div>

### What to do

 * The `longdesc` attribute is inconsistently implemented across browsers.  Where possible, it is preferable to provide a longer image description [using the `aria-describedby` attribute](https://www.w3.org/WAI/WCAG21/Techniques/aria/ARIA15);
 * OR, verify the `longdesc` attribute value is a valid URL of an HTML page with a text description of the image.

For example:

<CodeSnippet type="single" light={true}>&lt;img src="table.gif" alt="a complex table" longdesc="tabledescription.html" /&gt;</CodeSnippet>

</Column>
</Row>
</div>

export default ({ children, _frontmatter }) => (<React.Fragment>{children}</React.Fragment>)